Selective Grains & interfaces in service Silos of Heterogenous Clusters

Hello,

As agreed I will try to explain the situation.
First it's more of nuisance so it improves the Developer Experience at-least.

So scenario is like this where we have:
- Silo A
- Silo B

Silo A has:
- Grain A
- Grain B

Silo B has:
- Grain A
- but no Grain B (this is where Silo would break)

Grains here represent both present interface (GrainInterfaceType) with implementation (GrainType) running on a Silo.

From discussion on Discord there were some mentions of having to either duplicate the interface or create common assembly and include bare-minimum to each service Silo the interface of every Grain used in the Cluster for service Silo to function.

The issue names no files, tests, or entry points. Start by tracing Orleans grain interface and implementation registration for heterogeneous silos, then review the referenced Discord discussion. Done means defining and implementing a supported way for each silo to expose only the grain interfaces it needs without breaking cluster operation.

Written by the indexing model from the issue text.